Tertiary Bedrock

• Main Author: Ernest H. Lund
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1972
• Subjects: Seal Rock; Beaver Creek
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.624.5415; http://www.oregongeology.org/sub/publications/OG/OBv34n05.pdf

The Oregon Coast between Yachats and Newport is a narrow, slightly ele-vated coastal plain. With the exceptions of basalt rock at Yachats and Seal Rock, the bedrock along this segment of the coast is sedimentary (see map, page 74). Several Pleistocene marine terrace levels are discernible at places along the plain, and sand dunes, both active and stabilized, impart a roll ing topography to most of it. Numerous streams have incised sma II valleys and ravines into its surfacej at Waldport the plain is interrupted by the estuary of the Alsea River and at Ona Beach State Park by the alluvial plain of Beaver Creek. Except in the two localities where basalt is exposed, the shore is marked by long stretches of sandy beaches bounded by low sea cliffs. Where the basalt is exposed, the shore has the rugged features that are characteristic of Oregon shores bounded by this type of rock.